Rename nr_slot_fep_ul to nr_symbol_fep_ul to relfect its function
Simplify logic so that the function does not require RU context and
the implementation is not dependent on the implementation of RU buffer management.
This makes the function easier to understand and moves the responsibility
to set the correct buffer offset on the caller.
Introduce SRS physical simulator and improvements
This MR consists of two parts:
- Introduces SRS physical simulator to test different configurations of
SRS
- Improvements in the SRS channel estimation (Addressing the comments
from old, unfinished MR !2875)
- rewrite nr_srs_channel_estimation() to loop over rx antennas and
antenna ports to be able to parallelize
- Improvements in timing_advance_offset and timing_advance_offset_nsec
computation
- Introduce SRS multi-symbol channel estimation
- The channel impulse response is estimated from the averaged
channel frequency response over multiple symbols
- The channel frequency estimates are left as they are to be able to
estimate doppler in the future
- Simplify SRS channel estimation to handle memory alignment in the
case of different SRS configurations (eg: comboffset)
To use multiple symbols when running gNB, the following parameters needs
to be edited in the function get_srs_resource()
- srs_res->resourceMapping.startPosition with a range from {0,1,..,5}
corresponds to the start symbol {13, 12, .. 8} with in a slot
- srs_res->resourceMapping.nrofSymbols indicates the number of symbols
{n1, n2, and n4}
Make sure the that start symbol + number of symbols is < 14
The timing results for SRS in develop and srs_phy_simulator are as follows:
Command used: sudo ./nr_ulsim -n1000 -s50 -S50 -R273 -W2 -y2 -z2 -E 1 -P
develop
|__ RX SRS time 124.94 us (1000 trials) (124.94 total [ms])
|__ Generate SRS sequence time 0.05 us (1000 trials) ( 0.05 total [ms])
|__ Get SRS signal time 19.41 us (1000 trials) ( 19.41 total [ms])
|__ SRS channel estimation time 89.11 us (1000 trials) ( 89.11 total [ms])
|__ SRS timing advance estimation time 13.10 us (1000 trials) ( 13.10 total [ms])
|__ SRS report TLV build time 2.80 us (1000 trials) ( 2.80 total [ms])
|__ SRS beam report build time 0.00 us ( 0 trials)
|__ SRS IQ matrix build time 2.73 us (1000 trials)
srs_phy_simulator
|__ RX SRS time 211.93 us (1000 trials) (211.93 total [ms])
|__ Generate SRS sequence time 0.04 us (1000 trials) ( 0.04 total [ms])
|__ Get SRS signal time 19.55 us (1000 trials) ( 19.55 total [ms])
|__ SRS channel estimation time 152.05 us (1000 trials) (152.05 total [ms])
|__ SRS timing advance estimation time 36.67 us (1000 trials) ( 36.67 total [ms])
|__ SRS report TLV build time 2.96 us (1000 trials) ( 2.96 total [ms])
|__ SRS beam report build time 0.00 us ( 0 trials)
|__ SRS IQ matrix build time 2.88 us (1000 trials)
Note that in srs_phy_simulator, to compute timing offset ns, an
oversampling factor of 2 is performed. Also, for peak detection, we
average the channel estimates for every port.
Update physim timing thresholds in gNB-N300-Timing-Phytest-LDPC
The lower bound for the tests are too tight and any slight improvement
in the timing can result in a test failure. For example, these tests
were failing due to the improvements from the MR !3718
The lower bound for the tests are too tight and any slight improvement in the timing can result in a test failure.
For example, these tests were failing due to the improvements from the MR 3718
- Introduce signal energy and noise variance functions
- Combine rotation and OFDM modulation RX as a function
- Harmonize the use of number of antennas across the code
- Rename nr_ue_pusch_common_procedures() to nr_tx_rotation_and_ofdm_mod() to decribe the functionality better
Add symbol timing functions for NR_DL_FRAME_PARMS + optimization for slot timing
counterparts
Add two new functions for calculation symbol timestamp and symbol duration for
NR_DL_FRAME_PARMS. Also includes an optimization focused on removing
inefficiencies related slot-related counterparts.
1. Removed function pointers for functions get_samples_per_slot(),
get_samples_slot_timestamp() and get_slot_from_timestamp() as it does
not offer any advantage. The functions are now called directly from
everywhere.
2. Optimized these functions by removing loops where ever possible.
NR UE: calculate TA based on SIB19 information in NTN mode, if autonomous TA is not enabled
To achieve the goal, the hyper frame number (HFN) is introduced at the NR UE
PHY, MAC and RRC layers.
Besides this, we also implemented an orbit propagation to improve the accuracy
of N_UE_TA_adj, and a fix to keep the N_TA from RAR and MAC CE.
Fixes#981
E2SM-RC RRC message forwarding (e.g., to signal a new UE, measurement
reports, ...) was broken since commit d6c29b2d2c, as we accidentally
removed the E2_AGENT compilation definition from RRC layer.
Although this commit fixes the mentioned issue, it also causes undefined
references to functions defined in ran_func_rc.c file. Therefore, we
add a hack that provides the definition, and abort if we ever hit these
functions, which in theory should not happen.
Future cleanup should avoid linking in RRC and other layers into
simulators.
Fixes: d6c29b2d2c ("Fix E2_AGENT linking w.r.t. simulators ")
Consistently use OAI_RNGSEED env variable for RNG
use OAI_RNGSEED env variable everywhere. Hide normal table
initialization of Ziggurat generator from outside. Fix atoi() to use
stroul()
atoi() used previously does not capture all of unsigned long (so we
could not reproduce a high seed), and its use is discouraged as it does
not detect errors. Use strtoul() instead, which allows to also use other
bases (so we can e.g., write OAI_RNGSEED=0x1234)
Hide normal table initialization of Ziggurat generator from outside to
force the usage of randominit() for RNG initialization. In this step,
remove the randominit() seed parameter and only rely on OAI_RNGSEED for
a consistent RNG initialization, as this parameter was used differently
("0" as fixed number or to force a random seed).
Now, only use OAI_RNGSEED env variable to force the usage of a fixed
seed.
Implementation of STOP exchange
This implements the STOP.request/indication for all 3 transport mechanisms, the
VNF will send the STOP.request to the PNF, indicating it will disconnect, and
await a STOP.indication from the PNF
The WLS VNF is reworked to be able to start before the PNF, by calling call
rte_eal_init and rte_dev_probe to determine if dpdk has been initialized
properly, before calling rte_eal_init in the intended process when it is
appropriate to do so
Note: after this commit, monolithic works but nFAPI operation is broken
and fixed in the next commit, to keep the changes small(er). All
simulators work.
This commit removes the use of msgDataTx's intermediate buffers for FAPI
messages and the call of the "Schedule response". The latter incurs an
additional copy of FAPI messages for the TX chain (for the RX chain, it
is and will remain there) which we can avoid.
Instead, it uses an NR_Sched_Rsp_t-typed variable sched_response to
store the results of the scheduler when called from tx_func(). Thus, the
scheduler remains unchanged (it gets a pointer to where to put FAPI
messages), but we don't call nr_schedule_response() to then copy FAPI
messages into the L1, but have them in a local variable sched_response.
sched_response on on the data segment, as it is big and would overflow
the stack; at the same time, this is ok because only one tx_func() runs
at a time.
Since we don't use allocate_sched_response() anymore, we don't need
deref_sched_response().
clear_slot_beamid() is moved to tx_func(), as it was called in
nr_schedule_response().
Since the "intermediate" NR_gNB_DLSCH_t structure groups both the
DL_tti_pdsch and TX_data.req structures, a pointer has been created to
point to pdsch_pdu. This affects a number of simulators, as they have to
put some messages on the stack:
- nr_dlschsim: put the corresponding variable on the stack
- nr_pbchsim: a new array for the SSB PDUs has been introduced
Further, these changes are now necessary:
- nr_dlsim: there were variables "rel15" and "pdsch_pdu_rel15" that
point to the same PDSCH PDU. At least "rel15" would not exist, as the
corresponding pointer is now populated in phy_procedures_gNB_TX(), and
we therefore refer to the single PDSCH PDU variable with
"pdsch_pdu_rel15", but at the place where "rel15" used to be
initialized.
- nr_ulsim: use nr_save_ul_tti_req() to load PDUs into the RX chain
instead of nr_schedule_response(), which does not exist anymore.
The next commit will remove msgDataTx. We can therefore not use
msgDataTx to retain the PDSCH/DLSCH variables, and move them to the gNB.
Note that the only reason for NR_gNB_DLSCH_t after this commit is to
hold various large buffers (c, b, f). Future work could be done to
remove this, in which case the array inside PHY_VARS_gNB could be
deleted.
On this occasion, clean up the use of init_DLSCH_struct() and
reset_DLSCH_struct() (renamed destroy_DLSCH_struct()) and centralize
their call in phy_init_nr_gNB()/phy_free_nr_gNB(), and correct
simulators accordingly.
DLSCH encoding is not concerned with HARQ processes directly. Instead,
it gets the redundancy version and encodes a specific redundancy version
for a given TB. The rest is up to the MAC, the L1 is stateless in that
regard. Hence, remove the HARQ type and put it into DLSCH, which also
simplifies the code elsewhere.
There is no point in tracking the "active" state: the SSB PDU will be
sent from MAC to L1, encoded, and then "discarded" (by marking the
number of SSB PDUs as 0). Hence, remove this intermediate type.
Refactor DLSCH scheduler
Refactor the DLSCH post processor similarly to what has been done in
!3521 with the goal of saving an additional iteration through all UEs,
hopefully making the DLSCH scheduler faster.
It further includes changes to make working with and debugging multi-UE
operation easier:
- add some measurements in L1 (for total TX/RX time)
- a new option MACRLCs.[0].stats_max_ue to limit the number of UEs in
the periodic output (default: 8, 0=disable)
- avoid stack overflow in the MAC
- fix the writing of stats to nrMAC_stats.log and nrL1_stats.log when
the written output reduces by truncating the files
- avoid to schedule retransmission with 0 RBs.
saves about 600MB of memory allocation
Move the definition of PRACH items and the PRACH list to the
defs_nr_commons.h file.
Do not re-write the entire structure in nr_schedule_rx_prach(), as it is
quite large now.
Call the post-processor when the allocation is "fixed" (i.e., nothing
changes anymore), instead of having a final loop across all UEs that
might potentially be costly.
In order to calculate the PF metric, note that the statistics "reset" is
moved into pf_dl() instead of the post-processing loop, as it has to be
done on each slot.
See also: dd98030202 ("Refactor to call post-processor in place")
Similarly to parent commit(s), assign sched_pdsch in a single place
instead of relying on sched_ctrl. In a follow-up commit, the
post-processor will be called in a single place.
The function rx_nr_prach become autonomous, it doesn't read anymore global variables
So, it can become (later) a threadpool work, that will send a message when it finishes
rx_nr_prach_ru() still use some global variables, but it is executed in sequence, inside the ru main loop, that limits the probability of race conditions
Thomas Schlichter